A metal‐free approach for the synthesis of 5‐trifluoromethyl‐1,2,4‐triazoles from trifluoroacetimidoyl chlorides and hydrazones has been achieved under aerobic oxidative conditions. The reaction proceeds through a cascade base‐promoted intermolecular C−N bond formation and iodine‐mediated intramolecular C−N bond oxidative coupling sequence. The protocol features broad substrate scope and can be scaled
Iterative reactions of transient boronic acids enable sequential C–C bond formation
作者:Claudio Battilocchio、Florian Feist、Andreas Hafner、Meike Simon、Duc N. Tran、Daniel M. Allwood、David C. Blakemore、Steven V. Ley
DOI:10.1038/nchem.2439
日期:2016.4
allylic and benzylic boronic acids, obtained by reacting flow-generated diazo compounds with boronic acids, and their application in controlled iterative C–Cbond forming reactions is described. Thus far we have shown the formation of up to three C–C bonds in a sequence including the final trapping of a reactive boronic acid species with an aldehyde to generate a range of new chemical structures.
Addition reactions of organic carbanion equivalents via hydrazones in water
作者:Yi-Zhan Wang、Qi Liu、Liang Cheng、Song-Chen Yu、Li Liu、Chao-Jun Li
DOI:10.1016/j.tet.2020.131889
日期:2021.1
The addition of organometallic reagents to unsaturated bonds is one of the most powerful tools for carbon–carbon bondformations. Alkylation throughorganometallic reagents requires stoichiometric quantity of metal and tedious anhydrous operation in most cases. Here, we report “umpolung” nucleophilic additions of hydrazones to Michael acceptors, carbonyls and imines in water. Under the catalysis of
Rapid Asymmetric Synthesis of Disubstituted Allenes by Coupling of Flow-Generated Diazo Compounds and Propargylated Amines
作者:Jian-Siang Poh、Szabolcs Makai、Timo von Keutz、Duc N. Tran、Claudio Battilocchio、Patrick Pasau、Steven V. Ley
DOI:10.1002/anie.201611067
日期:2017.2.6
We report herein the asymmetric coupling of flow‐generated unstabilized diazo compounds and propargylated amine derivatives, using a new pyridinebis(imidazoline) ligand, a copper catalyst and base. The reaction proceeds rapidly, generating chiral allenes in 10–20 minutes with high enantioselectivity (89–98 % de/ee), moderate yields and a wide functional group tolerance.